I used the email address the dealer had setup my BMW Assist with.

Sending address via Google Maps works great on my 09 X5d. VERY nice feature since it is a pain to enter addresses manually....

I set up the email address when I did the initial call (from PCD). They asked for my everyday email, not one specific to BMW. My verizon.net account is what BMW assist has in their system.

When you s"end to car" from Google, it actually sends to BMW, and their server searches for the VIN number that is associated with your email address. Pretty cool, and very fast .